Copper (II) Chloride Formula

Copper (II) chloride, also known as cupric chloride, is a inorganic salt used as catalysts in chemical synthesis and is also used in the manufacturing of pyrotechniques for its blue/green colors.

Formula and structure: Copper (II) chloride chemical formula is CuCl₂ and the molar mass is 134.45 g mol^-1. The dehydrated form has a molecular mass of 170.48 g mol^-1. The structure of the anhydrous salt is formed by one cation Cu²⁺ and two anion Cl^-. The structure is a distorted octahedron with a copper cation bound to six chloride anions. In this dehydrated form, it is formed by a Cu²⁺ centered atom, surrounded by 2 water molecules and two chlorine anions Cl^-. Its chemical structure can be written as below, in the common representations used for organic molecules.

Occurrence: Copper (II) chloride, in its anhydrous or dehydrate forms, is found in some rare minerals as tolbachite and eriochalcite. This minerals are mostly found in fumaroles.

Preparation: Copper chloride is prepared from the reaction of metallic copper with chlorine:

Cu + Cl₂ + 2 H₂O → CuCl₂

Copper (II) chloride can also be obtained by the reaction of copper (II) hydroxide or copper (II) carbonate with hydrochloric acid:

Cu(OH)₂ + 2HCl → CuCl₂ + 2 H₂O

Physical properties: Copper (II) chloride is a blue-green solid when dehydrated and a yellow-brown solid when anhydrous. Copper (II) chloride density are 3.38 and 2.51 g mL^-1for the anhydrous and dehydrate forms. The melting point of the anhydrous salt is 498 °C and above 993 ºC the anhydrous salt decomposes. Copper (II) chloride is soluble in water, ethanol, methanol and acetone.

Chemical properties: Copper (II) chloride can suffer a diverse range of reaction, which make it versatile to use in different application in chemical industry or chemical synthesis:

It can suffer a redox reaction in the presence of a reductant. The formed compounds include metallic copper or cuprous salt:

2 CuCl₂ + SO₂ + 2 H₂O → 2 CuCl + 2 HCl + H ₂SO₄

With bases, copper (II) chloride can suffer a replacement to form copper (II) hydroxide:

CuCl₂ + 2 NaOH → Cu(OH)₂ + 2 NaCl

Uses: Copper (II) chloride can be used as a catalyst along with other chloride salts as the palladium (II) chloride. One of the uses is in the production of ethylene to acetaldehyde

C₂H₄ + PdCl₂ + H₂O → CH ₃CHO + Pd + 2 HCl

Due to its blue/green color, it is used in the manufacture of pyrotechnics.

Health effects / safety hazards: Copper (II) chloride is toxic in high concentrations. It can react with oxidizing agents. The compound is not flammable.